1. Field of Invention
The present invention relates to an electrical connection box and more particularly to an electrical connection box installed in the engine compartment of an automotive vehicle.
2. Description of Related Art
Various types of electrical connection boxes for various kinds of electrical devices, such as a junction box, a relay box, a fusible link box, and an electronic control unit for use in a car are known. When using these boxes it is necessary to avoid or minimize water leaking into the electrical connection box in order to keep the electronic components dry. In order to waterproof the electrical connection box a sealing packing is installed at a mating surface of the body and the cover of the electrical connection box to seal the box. This sealing is usually made of synthetic resin.
Relays and fuses are heat generating components. Thus, heat released from these components is retained in the sealed electrical connection box which raises the temperature within the box. Additionally, when the electrical connection box is placed in the engine compartment, the temperature inside the box is also raised due to the heat of the engine.
Electronic control units are increasingly used in cars. A typical electronic control unit (ECU) consists of an electronic circuit comprising heat-susceptible electronic components. When the environmental temperature increases the ECU, the characteristics of the electronic circuit may change thus decreasing the reliability of the ECU. In order to improve the heat resistance of the electronic circuit, it is necessary to use expensive heat-resistance electronic parts. These parts increase the entire cost of the car.
Because of possible reliability problems due to raising temperatures, an electrical connection box housing only the ECU is installed in the interior (passenger space) of the car. This reduces the environmental temperature of the ECU; however, this also increases the entire cost of the car by necessitating the need for additional interior car space of the car for accommodating the electrical connection box.
When an ECU for use in an electronic fuel injection apparatus (EFI) of an engine is installed in the interior of the car, it is necessary to wire a wire harness for connecting the engine and the electronic control unit. In this configuration, the wiring must be done from the inside of the engine compartment to the interior of the car. Therefore, it is necessary to use a long wire harness, which increases cost. It is also necessary to form a wire harness insertion hole on a car body panel partitioning the engine compartment and the interior of the car. This also increases the cost of the car.
JP-U-3-57978 (Utility Model) is one example of a prior art electrical connection box. In JP-U-3-57978 fuses are mounted in apertures of a wall of a sealed housing component of the box. Wires project away from the wall and are covered by a cover which locks onto a housing component.